The goal of this proposal is to further develop and adapt our existing DNA-based RNAi technology to a cell microarray format for high throughput gene function studies and potential drug screening efforts. The principle of arrays of living cells for "reverse transfection" has been established and applied to identifying cDNAs involved in cellular physiology changes. We will first utilize the published cell microarray method for our DNA-based RNAi system to prove the principle of microarrays of RNAi (MAR). We will then use the method to screen for genes the silencing of which will alter the expression of a reporter gene. This high throughput format of RNAi will impact the gene analysis and drug screening fields tremendously. Once we have developed this technology, we plan to take advantage of our strong collaborations and high market demand to distribute our RNAi systems throughout the biomedical field.